Phase diagrams of La1−xCaxMnO3\rm La_{1-x}Ca_xMnO_3 in Double Exchange Model with added antiferromagnetic and Jahn-Teller interaction

The phase diagram of the multivalent manganites $\rm La_{1-x}Ca_xMnO_3$, in space of temperature and doping $x$, is a challenge for the theoretical physics. It is an important test for the model used to study these compounds and the method of calculation. To obtain theoretically this diagram for $x<0.5$, we consider the two-band Double Exchange Model for manganites with added Jahn-Teller coupling and antiferromagnetic Heisenberg term. In order to calculate Curie and N\'{e}el temperatures we derive an effective Heisenberg model for a vector which describes the local orientation of the total magnetization of the system. The exchange constants of this model are different for different space directions and depend on the density of $e_g$ electrons, antiferromagnetic constants and the Jahn-Teller energy. To reproduce the well known phase transitions from A-type antiferromagnetism to ferromagnetism at low $x$ and C-type antiferromagnetism to G-type antiferromagnetism at large $x$, we argue that the antiferromagnetic exchange constants should depend on the lattice direction. We show that ferromagnetic to A-type antiferromagnetic transition results from the Jahn-Teller distortion. Accounting adequately for the magnon-magnon interaction, Curie and N\'{e}el temperatures are calculated. The results are in very good agreement with the experiment and provide values for the model parameters, which best describe the behavior of the critical temperature for $x<0.5$.Comment: 13 pages, 5 figure

Short-term reproducibility of nocturnal non-dipping pattern in recently diagnosed essential hypertensives.

Objective: To investigate in a selected population of patients with a recently diagnosed essential hypertension the short-term intrasubject variability of diurnal changes in blood pressure (BP). Methods: Two hundred and eight consecutive, recently diagnosed, never treated essential hypertensives (119 men, 89 women, 46 ± 12 years) underwent 24-h ambulatory BP monitoring (ABPM) twice within 3 weeks. Dipping pattern was defined as a reduction in average systolic and diastolic BP at night greater than 10% compared to average daytime values. Results: 177 subjects (85%) showed no change in their diurnal variations in BP. Of the 159 subjects who had a dipping pattern on first ABPM, 134 (90.6%) confirmed this type of profile on the second ABPM, while 15 (9.4%) showed a non-dipping pattern. Of the 59 subjects who had a non-dipping pattern on the first ABPM, 43 (72.2%) confirmed their initial profile on the second ABPM, while 16 (28.8%) did not. Conclusion: These findings indicate that short-term reproducibility of diurnal changes in BP in early phases of untreated essential hypertension, characterized by a large prevalence of dipping pattern, is overall satisfactory. However, our study underlines that also in this particularly selected population of hypertensives the definition of non-dipping status on the basis of a single ABPM remains unreliable in about one-third of patients

Left ventricular concentric remodelling and extracardiac target organ damage in essential hypertension

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The Clinical Impact of Methotrexate-Induced Stroke-Like Neurotoxicity in Paediatric Departments: An Italian Multi-Centre Case-Series

Introduction: Stroke-like syndrome (SLS) is a rare subacute neurological complication of intrathecal or high-dose (≥500 mg) Methotrexate (MTX) administration. Its clinical features, evoking acute cerebral ischaemia with fluctuating course symptoms and a possible spontaneous resolution, have elicited interest among the scientific community. However, many issues are still open on the underlying pathogenesis, clinical, and therapeutic management and long-term outcome. Materials and Methods: We retrospectively analyzed clinical, radiological and laboratory records of all patients diagnosed with SLS between 2011 and 2021 at 4 National referral centers for Pediatric Onco-Hematology. Patients with a latency period that was longer than 3 weeks between the last MTX administration of MTX and SLS onset were excluded from the analysis, as were those with unclear etiologies. We assessed symptom severity using a dedicated arbitrary scoring system. Eleven patients were included in the study. Results: The underlying disease was acute lymphoblastic leukemia type B in 10/11 patients, while fibroblastic osteosarcoma was present in a single subject. The median age at diagnosis was 11 years (range 4–34), and 64% of the patients were women. Symptoms occurred after a mean of 9.45 days (± 0.75) since the last MTX administration and lasted between 1 and 96 h. Clinical features included hemiplegia and/or cranial nerves palsy, paraesthesia, movement or speech disorders, and seizure. All patients underwent neuroimaging studies (CT and/or MRI) and EEG. The scoring system revealed an average of 4.9 points (± 2.3), with a median of 5 points (maximum 20 points). We detected a linear correlation between the severity of the disease and age in male patients. Conclusions: SLS is a rare, well-characterized complication of MTX administration. Despite the small sample, we have been able to confirm some of the previous findings in literature. We also identified a linear correlation between age and severity of the disease, which could improve the future clinical management

In-hospital and nine-month outcome of treatment of coronary bifurcational lesions with sirolimus-eluting stent

Between April 2002 and May 2004, 174 consecutive patients who underwent percutaneous coronary intervention of bifurcational lesions with sirolimus-eluting stents were identified. Two strategies were used: stenting only 1 branch (group 1S, n = 57) or stenting both branches (group 2S, n = 117). The incidence of major adverse cardiac events was evaluated in the hospital and at 9-month follow-up. There were no statistically significant differences between the 2 groups with regard to the incidence of target lesion revascularization (5.4% vs 8.9%, p = 0.76), target vessel revascularization (5.4% vs 11.1%, p = 0.51), and cumulative major adverse cardiac events (18.9% vs 23.3%, p = 0.76) at 9 months

A comparison of blood pressure control in a hypertension hospital clinic between 1997 and 2000

Aims: (1) To evaluate the prevalence of clinic blood pressure (BP) control in a large sample of treated hypertensives followed in our hypertension clinic during the year 2000, and to compare it with our 1997 data. (2) To investigate the prevalence of left ventricular hypertrophy (LVH) according to different levels of BP control. Methods and results: One thousand consecutive hypertensive patients who attended our hypertension hospital clinic in a period of 7 months during the year 2000 and who had regularly been followed by the same medical team were included in the study. LVH was assessed using two different electrocardiographic criteria (Sokolow-Lyon and Cornell). This population had similar clinical characteristics of a cohort including 700 patients seen at our centre during 1997 in which BP control rate was 34% (Cuspidi et al., J Hypertens 1999; 17: 835-41). During follow-up, 441 of the treated patients had clinic BP < 140/90 mmHg, 283 < 150/95 mmHg and 276 65 150/95 mmHg, indicating that BP control was satisfactory in 44.1%, borderline in 28.3% and unsatisfactory in 27.6% of the cases. Thirty-five patients (3.6%) had LVH according to Cornell criteria and 25 (2.6%) according to Sokolow criteria. A significantly lower prevalence of LVH was detected in patients with optimal BP control (<130/85 mmHg) compared to those with unsatisfactory BP (2.3% vs 9.4%, respectively, p < 0.01). Conclusion: The study demonstrates that: (1) hypertensive patients in a hypertension clinic have satisfactory BP control in 44.1% of cases, indicating a significant improvement of BP control in this clinical setting during the last 3 years; (2) prevalence of LVH is significantly related to BP control

Treatment of saphenous vein graft lesions with drug-eluting stents: immediate and midterm outcome

The purpose of the present report was to evaluate clinical and angiographic outcomes of drug-eluting stent (DES) implantation in saphenous vein graft (SVG) lesions